Answer:
FALSE!
Explanation:
Gymnosperms do use seeds but are exposed like the pine cones of pines. Angiosperms still have seeds, however, they flower or fruit.
Answer: A catalyst is a substance that speeds up the rate of a chemical reaction without being used up and remains chemically unchanged itself .
Explanation: For a reaction to take place the particles must collide with enough energy for bonds to break and reaction to occur .
BUT when a catalyst is present the reactants are able to react in a way that requires less energy ,leading to more successful collision so the reaction speeds up without the chemical composition of the catalyst being affected
NOTE: the catalyst must be chosen to suit the particular reaction
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Answer:
Benzene: 37.5 Torr
Methylbenzene: 12.5 Torr
Explanation:
By Raoult's Law, each substance in a gas mixture contributes to the total pressure of the mixture proportionally to their respective mole fraction. So,
Ppartial = x*P°
Where x is the mole fraction (0.5 for each one because it's equimolar), and P° is the vapor pressure.
Benzene: Ppartial = 0.5 * 75 = 37.5 Torr
Methylbenzene: Ppartial = 0.5 * 25 = 12.5 Torr
The hotter it gets, the faster molecules move, solid form is in low temperature, liquid in medium temperature and gas in high temperature.
Answer:
Mass = 0.697 g
Explanation:
Given data:
Volume of hydrogen = 1.36 L
Mass of ammonia produced = ?
Temperature = standard = 273.15 K
Pressure = standard = 1 atm
Solution:
Chemical equation:
3H₂ + N₂ → 2NH₃
First of all we will calculate the number of moles of hydrogen:
PV = nRT
R = general gas constant = 0.0821 atm.L/mol.K
1atm ×1.36 L = n × 0.0821 atm.L/mol.K × 273.15 K
1.36 atm.L = n × 22.43 atm.L/mol
n = 1.36 atm.L / 22.43 atm.L/mol
n = 0.061 mol
Now we will compare the moles of hydrogen and ammonia:
H₂ : NH₃
3 : 2
0.061 : 2/3×0.061 = 0.041
Mass of ammonia:
Mass = number of moles × molar mass
Mass = 0.041 mol × 17 g/mol
Mass = 0.697 g